I got it.
<a class="lbp-inline-link-1" href="#">Click Me</a>
<div style="display:none">
<div id="lbp-inline-href-1" style="padding: 10px;background: #fff">
<iframe id="mc-donation" src="https://app.mobilecause.com/form/aObfQA" width="550" height="1726"></iframe>
</div>
</div>
If you need button instead of plain text link, add button class like so – my button class happens to be x-btn.
<a class="lbp-inline-link-1 x-btn" href="#">Click Me</a>